PROJECT SUMMARY Tuberculosis (TB) is the world's second deadliest infectious disease, overshadowed only by HIV/AIDS. A prompt, accurate diagnosis is required for effective control of TB, but in endemic regions, patient management is initially based upon clinical suspicion and low-sensitivity sputum microscopy. Confirmatory culture testing is slow, costly, and not routinely available. There is currently a lack of early diagnostic tests, which, when combined with marginal clinical laboratory infrastructure, can result in the under- or over-diagnosis of TB. The former impacts successful patient outcomes and efforts to block secondary transmission, while the latter promotes unnecessary treatment and poor utilization of healthcare resources. The number of new TB cases diagnosed in the U.S. remains sizable, with a significant proportion of infections occurring in individuals who have limited access to health care, are foreign-born, and/or are HIV-infected. We have assembled a team of clinicians, TB experts, immunologists, and chemists to develop a new test for TB. Using surface-enhanced Raman spectroscopy (SERS) to significantly lower the limit of detection, we propose the development of an inexpensive, rapid, and accurate point-of- care immunodiagnostic assay utilizing multiplexed monoclonal antibodies to concurrently identify a panel of Mycobacterium tuberculosis target antigens that have been identified in body fluids during active infection. It is anticipated that a paired test to detect M. tuberculosis antigens in both serum and urine will significantly improve the overall sensitivity of antigen detection, redefining the way TB is managed. This approach is expected to provide the qualitative and quantitative data necessary for rapid, reliable diagnosis in a variety of settings, allowing the prompt accurate treatment of TB, as well as immediate infection control measures designed to avert transmission to others. The impact of the approach is amplified as the SERS platform can be adapted to the diagnosis of other infectious diseases by changing the array of detection antibodies.